title: Functional status and survival after kidney transplantation.
abstract: BACKGROUND
  Older patients constitute a growing proportion of U.S. kidney transplant recipients and often have a high burden of comorbidities. A summary measure of health such as functional status might enable transplant professionals to better evaluate and counsel these patients about their prognosis after transplant.
  
  
  METHODS
  We linked United Network for Organ Sharing registry data about posttransplantation survival with pretransplantation functional status data (physical function [PF] scale of the Medical Outcomes Study Short Form-36) among individuals undergoing kidney transplant from June 1, 2000 to May 31, 2006. We examined the relationship between survival and functional status with multivariable Cox regression, adjusted for age. Using logistic regression models for 3-year survival, we also estimated the reduction in deaths in the hypothetical scenario that recipients with poor functional status in this cohort experienced modest improvements in function.
  
  
  RESULTS
  The cohort comprised 10,875 kidney transplant recipients with a mean age of 50 years; 14% were ≥65. Differences in 3-year mortality between highest and lowest PF groups ranged from 3% among recipients <35 years to 14% among recipients ≥65 years. In multivariable Cox regression, worse PF was associated with higher mortality (hazard ratio, 1.66 for lowest vs. highest PF quartiles; P<0.001). Interactions between PF and age were nonsignificant. We estimated that 11% fewer deaths would occur if kidney transplant recipients with the lowest functional status experienced modest improvements in function.
  
  
  CONCLUSIONS
  Across a wide age range, functional status was an independent predictor of posttransplantation survival. Functional status assessment may be a useful tool with which to counsel patients about posttransplantation outcomes.
authors.affiliation: 1 Renal-Electrolyte and Hypertension Division, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA. 2 Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA. 3 Leonard Davis Institute of Health Economics, University of Pennsylvania, Philadelphia, PA. 4 Department of Medical Ethics and Health Policy, University of Pennsylvania, Philadelphia, PA. 5 Department of Biostatistics, University of Pennsylvania, Philadelphia, PA. 6 Philadelphia Veteran Affairs Medical Center, Philadelphia, PA. 7 Division of Nephrology, University of California-San Francisco, San Francisco, CA. 8 Department of Surgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA. 9 Division of Medical Ethics, New York University, New York, NY. 10 Division of Geriatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA. 11 Address correspondence to: Peter P. Reese, M.D., M.S.C.E., Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania School of Medicine, 917 Blockley Hall, 423 Guardian Drive, Philadelphia, PA 19104.
authors.forename: Peter P
authors.initials: PP
authors.lastname: Reese
authors.forename: Roy D
authors.initials: RD
authors.lastname: Bloom
authors.forename: Justine
authors.initials: J
authors.lastname: Shults
authors.forename: Arwin
authors.initials: A
authors.lastname: Thomasson
authors.forename: Adam
authors.initials: A
authors.lastname: Mussell
authors.forename: Sylvia E
authors.initials: SE
authors.lastname: Rosas
authors.forename: Kirsten L
authors.initials: KL
authors.lastname: Johansen
authors.forename: Peter
authors.initials: P
authors.lastname: Abt
authors.forename: Matthew
authors.initials: M
authors.lastname: Levine
authors.forename: Arthur
authors.initials: A
authors.lastname: Caplan
authors.forename: Harold I
authors.initials: HI
authors.lastname: Feldman
authors.forename: Jason
authors.initials: J
authors.lastname: Karlawish
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D015331:Cohort Studies; D051799:Delayed Graft Function / Q000209:etiology; D005260:Female; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D016030:Kidney Transplantation / Q000009:adverse effects / Q000401:mortality*; D019520:Living Donors; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012189:Retrospective Studies